Sizing composition and process of preparing the same



Patented Mar. 27, 1923.

PATENT OFFICE.

PHILIP W. CODWISE, OF DALTON, MASSACHUSETTS.

SIZING COMPOSITION AND PROCESS OF PREPARING THE SAME.

Ho Drawing.

To all whom it may concern:

Be it known that I, PHILIP W. Coowisu, a citizen of the United States, residino at Dalton, in the county of Berkshire, tate of Massachusetts, have invented certain new and useful Improvements in Sizing Com ositions and Processes of Preparing the ame, of which the following is a description, reference bein had to the accompanying drawing an to the figures of reference marked thereon.

This invention relates to the manufacture of size compositions suitable for use in the manufacture of paper, and more particularly to a sizing material prepared from certain forms of leather scrap.

I have found that by the treatment of alum tawed leather and preferably the waste or scrap discarded in the fabrication thereof, in the manner hereinafter disclosed, a sizing material is obtained which is, by reason of its penetrating and gelatinizin power and its other propert1es,highly suita le for use in sizin high grade papers.

The material which utilize in my process in the waste or scrap from alum tawed leather, which is a leather in which the animal tissues have been preserved by treatment with alum and salt. I place a convenient amount of the alum tawed leather waste or scrap, preferably in small pieces,

in a tub or vat, and Wash it with water to effect the removal of a considerable portion of the water soluble substances present, and particularly of the salt. A certain proportion of the alum present appears to be retained in the leather under treatment, and may convenientl be estimated as aluminium sulfate. The wash waters used as above described are discarded.

The washed leather scrap is then mixed with a definite amount of Wat/El; and heated by means of steam until the roper consistency of the liquid is reache or until the leather scrap is completely dissolved or dispersed in the liquid. I have found that for a high grade tub size, it is preferable to use approximately ten times by weight of water and that a suitable period for the steam cooking process is approximately twenty-four hours. It is readily apparent that these proportions may be varied in accordance with the specific raw material used Application flied February 27, 1919.

Serial No. 279,612.

and the character of the size desired, the proper preliminary tests as to viscosity, jelly strength, etc, being easily made by the methods ordinarily in use in paper making plants.

The sizing liquid thus obtained may, if desired, be used directly. In practice, however, I find it preferable to add to the liquid sufficient alum or aluminium sulphate in excess of that already present to bring the total amount of aluminium sulphate up to ten per cent of the dry weight ofsolids present in the size. After this addition, the size is cooked slightly to thoroughl incorporate and dissolve the alum. dditional preservatives may be used if desired, for example, zinc sulfate or formaldehyde.

The size which is directly prepared from alum tawed leather scrap by my method is of particular advantage by reason of its light color and of the fact that no filtering thereof is needed. \Vith most rades of alum tawed leather a clear solution is obtained which is suitable for sizing even the highest grades of white paper. In some cases, however, an o aque, li ht colored solution is obtained w ich is likewise suitable for the sizing of high grade papers, but may not be used where a clear solution is necessary. The solution obtained may preferably be applied to the paper by the usual tub sizing method well known in the art.

Having thus described my invention in a preferred form thereof, and without limiting myself to the specific proportions or periods of time recited therein, I claim:

1. A sizing material comprising a solution of the extractive and soluble matter of alum tawed leather, and containing aluminium sulfate.

2. A sizing material comprising a solution of the extractive and soluble matter of alum tawed leather, and containing aluminium sulfate to the amount of 10% of the dry solids therein.

3. In the process of preparing a sizing material, first washing and then extracting alum tawed leather by means of hot water.

4. In the process of preparing a sizing material, first washing and then treating alum tawed leather with hot water for a period sullicient to effect a solution thereof.

5. In the-process of preparing a sizing material, first washing and then dissolving alum tawed leather in hot water and adding aluminium sulfate thereto.

6. In the process of preparing a sizing material, first washing and then dissolving alum tawed leather in hot Water and adding aluminium sulfate thereto to a, total aluminium sulfate content of 10% Of the dry solid therein.

In testimony whereof, I afiix my 10 ture, in the presence of two Witnessee. PHILIP W. (JODWISEF Witnesses:

KATE- DEHEY, Jon A. Bnmows. 

